Weld head positioning apparatus



Jam 12, 1950 R. A. TIEDEMANN 2,920,856

WELD HEAD POSITIONING APPARATUS Filed Oct. 8. 1956 2 Sheets-Sheet 1 IN VEN TOR. RICHARD A IEDEMANN 2 Sheets-Sheet 2 R. A. TIEDEMANN WELD HEAD POSITIONING APPARATUS Jan. l2, 1960 Filed Oct. 8. 1956 Mullin; l

22 MHWHHIIIL IN V EN TOR.

RIUHAHB A L'EJJEMNN mi@ mags Yand that kof the other in a vertical plane.

United States Patent@ 1 ,.."""z,9`20,sf56 t WELD HEAD POSITIONING APPARATUS RichardA. Tiedemann, Milwaukee, Wis., 'assigner to A. 0. Smith CorporationQMilwauke/, Wis., a corporation `of NewYork Applicationv October: 8; '1956; Serial No. 614,724

l 'W6 "Clainisl" (Cll`248284) This invention relates to apparatus for positioning an automaticJweld head'and particularly to' 'animpr'oved actuating apparatusy for a folding pirallelograni support.

A welding head is normally supported on; the end of ya boom or the like which is adapted 'to dispose the end of the WeldingV electrode in the approximate welding position. Then, to laccurately position the end of the electrode,a line adjustment mechanism is provided which is adapted for relative small movement of the weld head.`

Forexample, a pivoting structurefor tine adjustment is disclosed and claimed in the applicants copending application which is.` assigned to a common'as'signe'ei'with the present;` application. The -cop'e'nding application is entitled, Welding'. Head Positionerpwith .Pate'ntfOice Serial No". v614,723 and tiled on the' same "date vas the l present application.

The present inventionprovides apparatus for moving the welding headin a generally vertical direction by the use of a folding parallelograrn structure.

In accordance with the present invention' a' bearing surface is provided in combination with thel means to secure to thelweld head to the parallelogram. `A triangularly-shaped pivoted member is pivoted about a rela- 4tivelystationary support and engages the bearing surface to effect a folding 1and' unfoldingof the par-allelogram.

The accompanying drawings illustrate' thebestrnode presently contemplated by the-inventor' for carrying out the invention.

` which is shown by phantom lines 4.

The boom 2 of which only. the free end is shown is a conventional horizontally disposed support which normally is pivotally supported-for rotation and for vertical movement through a"suitable.mechanism, not shown.

The rotating' structure 3 and weld head', shown by phantom lines 4, is shown for purposes of' illustration and is fully .disclosed and claimed "in the previously referred to copending application of the present applicant.

In general., the structure 3 disclosed in the copending application comprises a pairof hollow cylindersS secured to each other' with the axis of one 'in a horionta'l plane A shaft 6 is journaled in Y,t he.vertically disposed cylinder vand supports thewelfd'hed 4 by'a C-clamp 7,'of which only the ice lower portion. is'shown, 'securedto one'endof shaft 6.

A pivotal armS is secured to the opposite'end andpivoted about the 'axis of shaft 6 to pivot'the shaft and attached welding head. The arm'S is pivotedin any'suitable'manner, not'shown, `for"examp'le,' such as 'disclosed' 1in the; previouslyreferred to copending application'of `"RichardI A. Tiedemann.

A relatively stationaryisha'ft 9 is journaledsin'the horizontally disposed cylinderf'a` whichy pivots about the shaft 9 in response to pivotal movement of anarrnftltlfsecuredv totheouter surface ofthe'cylinder. i' VThe'stationaryshaftY 9 extendsfrom averticall'y disposed"rrrc'iuntingI plate'-11= engages the ends of each arm asshownvonlyfonthe farm'.

10 4in yFigure '1. Each shaft 15 extends transversely of th'el associated arms `and as thehandwheel 514;'is1turned-the' associated fshaft lmoves longitudinally and -pivotsfthe arm..

The pivoting :structure 3. and -weld l.headf4 gare. moved as a.y unitl in a' t vertical direction (by Vthe,n kparallellogtarri structurer-1which includes the` movable plate 1 2- to-fwhichthe2mountingpl-ate11'is-secured@ Thewparallelograni structure 1include s -:founarinsul disposeds-.to formf V`four edgesof -a parallelogr a n 1 structure with the forward end'17 of thearfns pivotally connected. to themovable plate 12 ,anda/Vith rearward ve11 l,.18.of the. armsfeonne c ted. .:t o Aa'A relati 'ely tationry. bracket 19 which,inturn, .,is securedgto he, boom. 2. l

As rnoreclea'rlyshV wn fn F .2,3thestationarybracket 19:'.is1` generally ladderes'ha'ped havingyeitically disposed and-spaced Vsidenrr'iembers 20y withaseries,ofvvertically spaced. connecting yokes `21 ijoining'the. side 1members. The bra'cliet19' is seeuredtothefboom `2v by. bolts 22 which.. pass through` suitable. lugsZalfinte'gra'lly formed with bracket`19 and thread into'boomgl, l A l Thezhracket side members 20, t fe'r inatefat leach end in apertured ears 24 to provide" a'bearing support` for an upper pin 25 and a lower pin 26. which pivotally support the arms. l. i t The ,rearward end"18'o ffeach ar'ml'also terminates in apertured ears andare secured'dnjl'tlie upper 'and lower pins 2 5 and 26, respectively, by snap rings 27"disposed one teach end of the pins." The'snap rings-27 snap into grooves 28 provided adjacent'each end-of the Apins 25 and 26. AThe"forni/arid end 17 of the"arms:similarly-terminate in apertured ears and are similarly secured tothe outer 'ends'lofan upper pin29 and a lower pin Sil-which are secured in the upper and lower edgey'ofthe movable plate12g" Snap rings 31 are snapped into grooves 32 adjacent leach end of the pins 29 and 30 to secure the arms tolthelpins. i

To provide a journal for the'upper p-in-29in theplate 12, theupper edge of the plate '12 is provided with a trans- 'vers'eopening receiving the upper pin 29. v

To provide journals for the lowerpinf30 in Ithe plate 12,`- apertured ears 33 are formed at eachof the lower 'corners of the plate 12 with the pin'30 journaled therein.

The plte^12 is` at all times maintained inavertical plane due to' thefolding'action of the parallelogram.

Tol control the position. of, the' plate.-12,-.an:.integral flange 34fextends`rearwardly from the-'upperedgefthe plate and provides a bearing surface for a triangularlyshaped pivotalmember 35. i Thel ange 34? is, Ishown integrally formedwith the Yplate 12.'

As more clearly shown in Fig. 2, the triangularly-shaped pivotal member 35 is a generally triangular shaped mem-1 ber keyed at an apex to a shaft 36 as by key 37. The: shaft 36 is journaled in a cylinder 38 which extends for-- wardly from an intermediate yoke member 21. The other' two apexes of the triangularly-shaped pivotal member 35' are bifurcated to receive rollers 39 and 40 which are each journaled on a shaft 41 which is secured one within the: arms of each apex.

When the triangularly-shaped pivotal member 35 is: pivoted about the cylinder 38, as more fully described: hereinafter, the roller 39 engages the underside of the; flange 34 and supports the flange 34 and attached plate: 12. If the triangularly-shaped pivotal member 35 is ro tated in one direction, shown as counterclockwise in Fig. 2, the flange 34 and plate 12 are forced upwardly. If the triangularly-shaped pivotal member 35 is rotated in the opposite direction, the flange 34 and plate 12 are lowered by the weight of the attached welding head 4 and the rotating structure 3 gravity biasing the parallelogram structure to a folded position.

The cylinder 38 within which the shaft 36 is journaled is integrally formed with and extends forwardly from the yoke member 21 of the bracket 19 to dispose the triangularly-shaped pivotal member 35 forwardly of rear edge 42 of the flange 34. The previously described movement of the plate 12 is in a small arc and the triangularly-shaped pivotal member 35 is therefore disposed somewhat intermediate the flange to prevent the flange from moving forwardly and disengaging the triangularly-shaped pivotal member.

Pivoting of the triangularly-shaped pivotal member 35 is controlled by a longitudinally moving shaft 43 through a threaded embossment 44 which is in the same vertical plane as the triangularly-shaped pivotal member 35. The shaft 43 threads through the embossment 44 into biasing engagement with the roller 40. When the shaft 43 is lthreaded toward the roller 40, it pivots the triangularlyshaped pivotal member 35 in a counterclockwise direction and when it is threaded away from the roller 40, it pivots the triangularly-shaped pivotal member 35l in' a clockwise direction respectively raising and lowering: the plate 12.

A small handwheel 45 is keyed as by key 46 to the outer end of the shaft 43 to facilitate operation of the shaft 43 and the resulting movement of the triangular-ly* shaped pivotal member 35.

The threaded embossment 44 is supported by an arm 47' extending from the one vertical side member 19.

As shown in Fig. 2, a similar threaded embossment 48` is secured to the opposite vertical side member by an arm 49 to allow the apparatus to be changed for manual control from the opposite side of the parallelogram structure 1. To change to right hand control, the threaded shaft 43 is transferred to the right-hand embossment 48 and the triangularly-shaped pivotal member is removed from the shaft 36 and turned to dispose the roller 39 in engagement with the end of the shaft 43 and the roller in engagement with the undersurface of the flange 34.

A strengthening plate 50 may be employed between the arms 47 and 49 and the lower bracket yoke 21 to add rigidity to the arms. The plate 50 is horizontally disposed and welded or otherwise secured to the arms and the yoke.

The present invention provides a simple, rugged actuator for a parallelogram support for'fine adjustment of the position of a welding head.

Various modes of carrying out the invention are contemplated las being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. A folding parallelogram apparatus adapted to be secured to a relatively stationary support and having a vertically movable forward member adapted to support a member, which comprises a bearing member extending laterally from the forward member, a pivotal means hav- `ing at least three apexes and disposed beneath said bearing surface, said pivotal means being adapted to be pivoted about one of said apexes to dispose a second apex into engagement with the undersurface of the bearing member to support the forward member and to move the forward member, and means engaging the third apex to pivot the pivotal means.

2. A folding parallelogram structure adapted to be secured to a relatively stationary support and having a vertically movable forward member and means to secure a member to said forward member, said member gravity biasing the forward member downwardly to fold the parallelogram, which comprises a rearwardly extending flange secured to the forward member, a pivotal means having a plurality of apexes and being disposed beneath the flange and pivotally supported at one apex of said :pivotal means, and means to pivot the pivotal means about l the supported apex to effect engagement between the flange and another apex of the pivotal means and thereby effect a lifting of the forward member and the member .against said gravity bias.

3. In a folding parallelogram structure having a stationary support and a movable plate joined by four pivoting arms, a flange extending rearwardly from the upper edge of the plate toward the stationary Support, a pivotal member pivotally journaled within the space defined by said four arms and having a bearing surface, .and means to pivot the pivotal member to bring the bearing surface into lifting engagement with said flange to raise and lower said movable plate.

4. A Weld head positioner, which comprises a gener- :ally rectangularly shaped support bracket, four arms piv- 'otally attached one to each corner of the bracket, a generally rectangularly shaped movable plate, pivotal means to secure the outer end of said four arms to the four corners of the movable plate to provide a folding parallelogram, a flange extending rearwardly from the upper edge of the movable plate toward the support bracket and adapted to move between the adjacent arms, a .shaft extending from an intermediate portion of the support bracket and terminating beneath the flange, a tri- .angular member journaled at one cam apex on the end of the shaft, a transversely moving rod adapted to en- ,gage a second apex of the triangular member and to thereby pivot the triangular member about the shaft and bring the third apex into moving engagement with the flange to control the position of the movable plate, and Vimeans to support said rod.

5. A weld head positioner, comprising a pair of spaced vbracket members, four arms pivotally secured to the brackets in spaced relation to form a folding parallelogram structure, means to secure one of said brackets to .a relatively stationary support with the arms adapted to pivot in vertical planes to vertically position the other of said brackets, means to secure the other of said brackets to a welding head, a pivot shaft extending forwardly from said first named bracket and terminating in spaced relation to the second named bracket within the space described by said arms in an unfolded position, a triangular shaped member journaled at a an apex on the shaft, a shaft disposed transversely of the parallelogram structure with one end engaging a second apex of the triangular shaped member and movable in a longitudinal direction to pivot the cam about the shaft, a journal secured to one vertical edge of the first named bracket and having the longitudinally movable shaft journaled therein, a flange extending rearwardly from the upper edge of the second named bracket toward the first named bracket and over the triangular shaped member whereby the third apex of the triangular shaped member is maintained in engagement with the undersurface of the flange to move the flange and the attached bracket in a generally vertical direction, and a second journal secured to the other vertical edge of the rst named bracket to a1- low journaling of a shaft therein and control of the triangular shaped member i rom the corresponding side of the paralleiogram.

6. A weld head positioner in accordance with claim 5 having rollers secured to the second apex `and to the third apex to provide a rolling contact with the shaft and the flange.

References Cited in the file of this patent UNITED STATES PATENTS 

